Rear-light indicator for automobiles.



PATENTED OCT. 2

/ L. P. MURPHY. REAR LIGHT INDICATOR RoR RUTOMORILRR.

APPLICATION FILED SEPT. 5. 1905.

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LEO FRANCIS MURPHY, OF DETROIT, MICHIGAN..

REAR-LIGHT INDICATOR FOR AUTQMQBILES No. saaie?.

Specification of Letters Patent.

Patented Get. 2, 1906;

Application led September 5, M305. Serial No. 277,062T

To all whom `t mag/'concerns v Be it known that L Lno FRANCIS MURPHY, a citizen of the United lStates of America, re-` siding at Detroit,.in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Rear-Light Indicators for Automobiles, of which the following is' a specification, reference being had therein to the accompanying drawings.

The invention relates to a device especially designed for use in connection with automobiles for the purpose of indicating to the driver the condition of the rear light.

The rear light, the use of which on automobiles 'and similar vehicles is in many places required by law, is usually so located that it is impossible for the driver to inspect the same without leaving his seat. As a con sequence he is either ignorant ofthe condition ofthe lamp or it is necessary for him from time to time to leave the car to inspect the same.

It is the object of my invention to provide an indicating device thatwill immediately call the attention of the driver to the fact that the rear light is out and,`urthermore, to provide means by Which the driver may at any time test the operativeness of the indicater, as hereinafter set forth.-

In the drawings, Figure l is a view illu trating in side elevation and in dotted lines an automobile to which my improvement is applied, the lamp, the indicating electric circuit, and the indicator being shown in full lines. Fig. 2 is a diagram of the indicatingcircuit, including ,the thermo-electric switch and the indicating-lamp. Fig. 3 is a similar view illustrating a modification. Fig. i is a sectional elevation oi the rear lamp with my attachment applied thereto. Fig. 5 is a section on line 5 5, Fig. 4, illustrating securing means of the thermo-electric switch toa rear lamp.

A is a rear lamp of any suitable construction, which is attached to the body of the vehicle orto other suitable support by the bracket B. The indicator WhichI preferably use in connection with this lamp comprises a thermo-electric switch C,'included in an electric circuit D and so located in rela-A tion to the lamp A as to be influenced by the heat of said lamp whenlighted.

E is th'in'dicator for which Ipreferably employ a miniature electric lamp included in the electric circuit D, which is4 also providedto the indicator-*lam E an with a suitable battery or'other electric generator 'F 4on wiref.

As illustrated in Figs. 2 and 4, the switch c comprises a' composite bar a, which is formed .oi two metals having different co, efficients of expansion, and this bar is preferably bent into the curved or return-bent form illustrated. One end of this bar is" riglater-support upon the'lamp,while the opposite endfree to move under the influence of expansion. c is an electric l.contact which is arranged in proximity to the free end of the bar a, being preferably adjustable and also preferably in normal contact with said bar when the latter is not heated. i

`'Ihe switch C is so located in the lamp that the curved portion of the bar a, is subjected to the heat of the lamp when lighted and under the iniiuence of this heat Will be eX- panded, causing the outward movement of the iree end of the bar and the separation of the same from the contact c. 'Thus when the lamp is lighted the circuit D will be broken, and the indicator-lamp E will not be cated at a point where it will be under the obl servation of the driver, preferably upon the dashboard. As a consequence it at any time the indicator-lamp is illuminated it will at once direct the attention oi the driver to the fact that something is wrong with the rear light. This will be understood, as it is apparent Athat as long as the bar a remains heated it will be separated from the contact c; but just as soon as the bar is cooled contraction will take place, which will close the electric circuit and cause the illuminationof the indicator-lamp E.

The arrangement above described would be sufiicient but for the fact that some, derangement of the apparatus, such as the breaking of the electric circuit at some other point or the failure of the batteries, would render lit inoperative. Thus -the `driver would have no assurance that the indicator was inoperative condition. To avoid this diiiiculty, I preferably provide means for at any time testing the operativeness of the circuit, such as illustrated in Fig. 3, in which F is a lswitch preferably arran ed in proximity under the control of the driver. is a second. electric contact which is arranged upon the opposite side of the bar a, from the contact c and is so' Vidly attached, as by the screw b, to an insu` illuminated. The indicator-lamp 4E is lo- ICD IIO

adjusted that when the bar a is heated it erating, whereas if 'the lamp Eis not illuminwould be in contact with. d.

a tliree-pole switch, by means of which the main circuit may be closed through either that portion includirngr the contact c or the branch e, including the contact d. The switch li" is also preferably provided with an indicator for its operating-lever, this indicati` ing which circuit closed in each position ot adjustment. Thus if the other parts of the apparatus arel arranged as previously `described the driver may at any time move the switch F whereupon if the lamp A is operating, and the bar av consequently expanded., the circuit will be closed through the contact d and branch c and the indicator -lamp E will be illuminated. If the lamp A is not operating, the circuit will be closed, and the lamp E will be illuminated when the switch F con* nects poles in the main circuit. switch may also be used to cut out the indicatorlam p E when the lamp A is purposely turned out. lamp A is lighted any failure on the. part of the operator to turn the switch F will at once be called to his attention, as the indica tor-lamp E will be illuminated and the indications in connection withy the switch F, suchv the words l Normal and Test, will show which position the switch should be turned in for normal operation. If the lamp E is illuminated when the indicator is set at Test, the driver will know that the rear lampis not operating. If the lamp E is not illuminated, the driver may move the indicator to Normah and the lamp E will then be illuminated to show that the lamp A is op- This testing- Furthermore, whenever thel c is a branch i ated in either position of the indicator it will electric circuit extending iroin the contact d to the switch F', and this switch is prelerably show that one of the circuits is out of order.

What I claim as my invention is 1. The combination with a lamp, of a thermo-electric switch associated therewith [to be operated thereby, a plurality of electric circuits controlled by said switch, an electric indicator-lamp included in said circuits, and a second switch controlling said circuits for the purpose described.

3. The combination with a lamp, of a thermo-electric switch associated therewith to be operated thereby, a pair of electric circuits. alternately controlled by said switch. an electric indicatorlamp included in one of said circuits, and means for indicating which circuit is closedyior the purpose described.

4. The combination with a lamp, of a thermo-electric, switch associated therewith to be operated thereby, an electric circuit arranged 'to be closed by said switch when in one position, a second electric circuit arranged to b e closed by said switch when in another position, and means for indicating which circuit is closed.

In testimony whereof I aiiix my signature inpresence of two witnesses.

LEO FRANCIS MURPHY.

Witnesses:

J AMES P. BARRY, EDWARD D. AULT. 

